com.happy_coding.viralo.mongodb.MongoConnection.java Source code

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Here is the source code for com.happy_coding.viralo.mongodb.MongoConnection.java

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/**
 * Copyright (C) 2012 Happy Coding <contact@happy-coding.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.happy_coding.viralo.mongodb;

import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.Mongo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * MongoConnector.
 * <p/>
 * Indexes:
 * <p/>
 * db.friends.ensureIndex({authenticated_uid:1, uid: 1},{unique:true});
 */
public final class MongoConnection {

    /**
     * Logger.
     */
    private Logger logger;

    /**
     * Mongo handler.
     */
    private Mongo mongo;

    /**
     * Mongo DB.
     */
    private DB database;

    /**
     * the mongo connection instance for the singleton.
     */
    private static MongoConnection instance;

    /**
     * The available collections.
     */
    public enum CollectionName {
        FRIENDS, FOLLOWERS, TWEETS
    }

    /**
     * returns an instance to the MongoDB database.
     *
     * @return the mongo connection
     */
    public static synchronized MongoConnection getInstance() {
        if (instance == null) {
            instance = new MongoConnection();
        }
        return instance;
    }

    /**
     * the constructor.
     */
    private MongoConnection() {

        logger = LoggerFactory.getLogger(getClass());

        String mongoServer = System.getProperty("mongoserver");
        String mongoPort = System.getProperty("mongoport");
        String mongoDatabase = System.getProperty("mongodatabase");

        try {

            /*
             * load addresses from properties file
             */
            mongo = new Mongo(mongoServer, new Integer(mongoPort));

            database = mongo.getDB(mongoDatabase);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * return database.
     *
     * @return mongo db
     */
    public DB getDatabase() {
        return database;
    }

    /**
     * Returns the collection with the given name.
     *
     * @param collectionName name of the collection.
     * @return the MongoDB collection.
     */
    public DBCollection getCollection(CollectionName collectionName) {

        String name = collectionName.toString().toLowerCase();

        return database.getCollection(name);
    }
}